1. Technical Field
The present disclosure relates to an impact energy absorption structure for a vehicle, particularly to an impact energy absorption structure for a vehicle, that houses an impact absorption member formed of a resin inside a hollow closed-section body such as a center pillar.
2. Related Art
In a typical vehicle, a hollow closed-section body is formed by a joint structure that joins an outer panel and an inner panel made of a steel plate, and the structure constitutes the main framework of the vehicle. For the joint structure, sufficient strength is needed in order to secure the safety of occupants when an impact is applied to the structure in a collision accident or the like. In order to satisfy the need, for instance, a reinforcement member may be disposed in the space between the outer panel and the inner panel.
Referring to Japanese Unexamined Patent Application Publication (JP-A) No. 2013-212730, it is described therein that a reinforcement member containing of a resin is disposed between an outer panel and an inner panel. Referring to FIG. 4, an outer panel 104 and an inner panel 102 are joined together to form a center pillar 100, in the closed-section space of which a reinforcement 106 is disposed. Since the reinforcement 106 is included in the center pillar 100, an impact energy at the time of a collision is absorbed by deformation of the reinforcement 106, and thus the safety at the time of a collision is improved.
Also, the reinforcement 106 is formed in a grid pattern by ribs 108 extending in a widthwise direction on the paper surface and ribs 110 extending in a lengthwise direction on the paper surface. This achieves the effect that strength and stiffness are appropriately designed and the safety at the time of a collision is improved.
However, in the invention described in JP-A No. 2013-212730, referring to FIG. 4, the reinforcement 106 housed between the outer panel 104 and the inner panel 102 has an uniform thickness in a vehicle width direction. Thus, there has been a problem in that when an impact energy is applied to the reinforcement 106 at the time of a collision accident, the reinforcement 106 is crushed overall in a relatively short time and the impact energy is not sufficiently absorbed.